A woman who said she came to the defense of a passenger who was being thrown off a Red Line train spoke about the incident Friday.

Selena Lechuga, 22, was seen on cellphone video spitting at a Los Angeles police officer after she was handcuffed and taken away for what police called interfering with an investigation at the MacArthur Park station.

"I just did what I thought natural to happen," she said. "I do believe that I witnessed a social injustice and I acted as any civilian would act in any situation such as this."

Lechuga would not talk about whether she spit on the officer because of the ongoing investigation. But she said she was heading to a culinary job when she saw the confrontation between 18-year-old Bethany Nava and the officer.

Community activist groups joined Lechuga at a news conference using what happened as a platform to get the MTA to change its rules when it comes to policing public transportation.

"We're asking you to support our campaign for free public transportation, to have no police on the trains and buses, to decriminalize fare evasion, there's no so-called 'codes of conduct,'" said Eric Mann, with the Labor and Community Strategy Center.

The MTA provided a written statement to Eyewitness News.

"Safety and security is our No. 1 priority. Metro continues to work with our partners at the Los Angeles Police Department on this investigation to gather all the facts."

The LAPD said it is investigating what happened.

When asked about the criticism she received about the officer being right and her actions being wrong, Lechuga said she will fight for what she believes in.

"I'm fighting for you whether you agree with me or not. I am with you, I am for you, I am trying to move forward from this," she said.

The young woman who was thrown off the train hasn't spoken publicly about what happened.

No charges have been filed against Lechuga, but she has a court date on Feb. 16.